Machine for grinding shaving-machine blades



M. w. MOLLER AND A. E. HARMS.

MACHINE FOR GRINDING SHAVING MACHINE BLADES.

APPLICATION FILED AUG. 1, 1918- Patented Oct. 11, 1921.

InvenZOiS sharpened.

UNITED STATES MORTEN WILHELM MLLER AND ALBERT EJNAR HARMS, OF COPENHAGEN,

DENMARK, ASSIGNORS TO MEKANISK IN DUSTRLCOMPANY LTD, 0 COPEN- HAGEN, K, DENMARK.

MACHINE FOR GRINDING SHAVING-MACHINE BLADES.

To all whom it may concern:

Be it known that we, MORTEN WILHELM MoLLER, engineer, and ALBERT EJNAR HARMs, wholesale merchant, residing at Copenhagen, N o 11 Fredenhsgade, Denmark, have invented certain new and useful Improve-g ments in Machines for Grinding Shaving Machine Blades,.of which the following is a specification.

The object'of the present invention is to provide a machine for grinding the blades of safety razors. The machine is of the type wherein two grinding rollers are provided, which rotate first in one-direction and then in the other, and wherein a bladeholder is arranged between the rollers whereby the four sides of the two edges of the blade are Experience has shown that the grinding of all four sides exactly alike is attained with difficulty, and the object of the present invention is therefore to produce a machine which automatically executes the reversal of the blade after the conclusion of each grinding period in one direction in such a mannerthat each grinding period is con trolled, thereby insuring that the grinding periods in each direction of rotation of the grinding wheels are of exactly the same duration; or in other words; the length of grinding surface which operates upon the blade is the same during the rotation of the rollers in each direction.

The invention is shown in the accompanyin drawing,'in which:

Tigure 1 shows the front view of the machine with the front plate removed.

Fig. 2 is a section taken on the line II--1I 'of Fig. 1.

Fig. 3 shows a detail "of the blade holder in longitudinal section. "Fig. bis an end. elevational detail of the blade holder.

Fig. 5 is a longitudinal section of the blade holder on a plane at right angles to Fig. 3.

' Fig, 6 is a front view of a modified form with the front plates removed.

In carrying out the invention according to one mode, the machine consists of a motion transmitting mechanism, inclosed between plates3 and 4,for two grinding rollers 7 and 8, together with a reversible blade holder Specification of Letters Patent.

Application filed August 1. 1918.

Patented Oct. 11, 1921. Serial Nb. 247,885.

(not shown in the drawings) carried by the spindle 9,

The two grinding rollers mounted on pivots 1 and 2, wheels 5 and 6 cooperating rack element in the form of a' toothed segment 11, the nave 18' of which is provided with a handle D and is rotatable about a pivot 12.

By operating the toothed segment 11 alternately in the one and in the other directron, the two grinding rollers will rotate alternately counterclockwise and clockwise.

Theblade holder consists of a cylinder or the like 22, provided with two slots and mounted on a pivot 9 with gear wheel 10. The blade A is placed between two cheeks 24, which may have studs 25 corresponding to holes,-if any, in the blfade A and this together with the two cheeks 24 may now slide down in the cylinder so that the two edges of the blade protrude through the slots 23.

Two blade springs 20 and 21 are provided to control the oscillation of the lever 16 and to restore it to its normal position.

The apparatus operates as. follows 7 and 8 are fitted with gear with a toothed When the handle D is moved alternately to one side or the other, the two grinding rollers 7 and 8 will becaused to rotate in a manner previously explained. At the same time the cam 19 will engage the tip ofthe lever 16 and dotted lines one of the two positions which the lever occupies when acted uponby the cam), and this movement will be transmitted to the swing arm 13, so that the toothed part thereof will cause the gear wheellO to rotate, thereby turning the blade holder 9 over, sothat its position is reversed and the other two sides of the cutting edges of the blade A will b pressed againstthe grinding rollers. w

When the toothed segment has reached the end of its movement in one direction, the tip of the lever 16 will be free of the cam 19, when, by virtue of the elasticity of the blade (under its pressure against the grinding rollers) and the action of the two springs 20 and 21, it will assume its vertical position, in which the tip of the lever 16 will lie behind the oppositeend of the cam.

push it aside, (Fig. 1 shows in wheels 5 and caused to assume shaped end to engage By moving the toothed segment back in the other direction, by operation of the handle D, the end of the cam will engage the lever 16, canting it over in a direction opposite to that shown in dotted lines in the drawing, whereby the blade holder will be again reversed. 7

It will be observed that the duration of the period of grinding in each direction is the same, this being controlled in such a manner that the handle D cannot be reversed until its full stroke has been accomplished by reason of the cooperation between the member 16 and the cam 19, the engagement between these two members being such that reversion cannot take place while the tip of the member is upon the curved surface of the cam, but must be permittedto be free thereof and 1e in a vertical position at one end or the other of the cam before the bandle can be reversed.

In the modification shown in Fig. 6, swing arm 13 is dispensed with. In this form a lever 16' is applied directly on the pivot 9, and is formed with a roundedor suitably thesurface of the cam 19, which may be-mounted upon the toothed segment 11 rotatable about pivot 12. A spring 21"is provided to control the movement of the lever 16' tendin to return it to its normal or mid position. pair ofgrinding rollers 7, 8' are provided with. gear 6 engaging with toothed segment 11. h h

In operating the device according to this form, as the handle D is moved from left to rig t gages the lever. 16', turned about its pivot 9" into the dotted position shown on the right of the center line, passing through said spindle, so that the end of the drawing, the cam 19 enand causes it to be of the lever 16 rests on the surfaceiof the.

cam 19', permitting the latter toslide beneath it. While inthis position, anyreversal of the handle will not produce a consequent turning over of the lever, and this will not take place until the latter has slipped down behind the other end of the cam; Upon the reversal of the-handle D at the completion of its stroke, the lever is i the other position shown. When not engaged by .the cam the lever occupies the midposition shown in full lines. Having now described our invention, what we claim as new and desire to secure by Letters Patent is y '1. Grinding apparatus for safetyrazor blades, comprising a frame, a pair of grinding rollers carried by said frame, gear wheels provided onsaid rollers, a pivoted member comprising a cam member, toothed segment engaging with said gear wheels and an-oscillating handle attached to the pivoted member whereby said pivoted member may be ment engaging with said gear oscillating handle attached to the pivoted manually oscillated, a blade holder and means adapted to contact with said cam for maintaining the blade in contact with the rollers during their oscillation and for oscillating the blade holder.

2. Grinding apparatus for safety razor blades, comprising a frame, a pair of grinding rollers carried by said frame, gear wheels provided on said rollers, a pivoted member comprising a cam member, a toothed segwheels and an member whereby said pivoted member may be manually oscillated, a blade holder and a pivoted lever, adaptedto be engaged by said cam member for maintaining the blade in contact with the rollers during'their oscillation and for oscillating the blade holder.

3. Grinding apparatus for safety razor blades, compri ing a'frame, a pair of grinding rollers carried by said frame, gear wheels provided on said rollers, a pivoted member comprising a cam member, atoothed segment engaging with said gear wheels and an oscillating handle attached to the pivoted member whereby said pivoted member may be manually oscillated, a blade holder, a I

pivoted lever operatively connected with saidblade holder and resilient means normally holding said pivoted lever with one end in the path of said oscillating cam memher, said cam member being of a length to y 7 .release said pivoted lever at the end of an oscillation of the cam and engage said pivoted lever on a return oscillation. to turn the blade into operative contact with the grinding rollers. r

4. Grindingapparatus for safety razor blades, comprising a frame, a pair of grinding rollers carried by said frame, gear wheels provided on said rollers, a pivoted member comprising acam member, a toothed segment engaging with said gear wheels and an oscillating handle attached to the pivoted member whereby said pivoted member may be manually oscillated, a blade holder ,provided with a'gear arm' having teeth gear wheel of the blade holder a pivoted lever one end? of which isoperatively con nected with one end of said. pivoted swing. arm, and. resilient means normally holding the other end of said pivoted lever in the path of said oscillating cam member, said cam member being of a length to release said pivoted lever at the end of anoscillation of the cam and engage said pivoted 1ever on a return oscillation to turn the blade into operative contact with the grinding I roller.

'5. Grinding apparatus for safety razor wheel, a-pivoted swing adapted to engage theblades comprising a frame, a pair of grindmember comprisingacam member, atoothed Versal of the rollers before the end of a 10 segment engaging with said gear Wheels and stroke.

an oscillating handle attached to the piv- In testimony whereof We afiix our signaoted member whereby said pivoted member tures in presence of two Witnesses.

may be manually oscillated, a blade holder, MORTEN WILHELM MOLLER. means adapted to contact with said cam for ALBERT EJNAR HARMS.

v maintaining the blade in contact With the Witnesses:

rollers during their oscillation for oscillat- CHARLES UNDE, ing the blade holder, and for preventing re- E. WVEIL PKOW. 

